Carbonizing or case-hardening low-carbon steel.



* T @1351 PATNT @EFKQE.

GH BODMAN, OF PITTSBURG, PENNSYLVANIA} CARBONIZING 0R CASE-HENING LOW-CARBON STEEL.

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To all whom it may concern:

Be it known that I, HUGH RODMAN, a citizen of the United States, and a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Carbonizin or Case- Hardening Low-Qarbon Steel, 0 which the following is a specification.

- This invention relates to the art of carbonizing or case-hardening low carbon steel or iron and to cementing material for use therein.

I have found that many coals, especially the soft coals, by which I mean bituminous coal, cannel coal, lignites and peats, develop active cementing properties when mixed with various 'compoun s of the fixed bases for example Ca, Ba, Na, K and the like and produce cementing material which will not mar thesurface of the metal parts treated.

I have found that b mixing bituminous coal, such as is general y found in the Pittsburg district, Colorado lignites, cannel coals and peats from various localities, with, say, 10%- of powdered lime and 5% ofsoda-ash, or, say, 25% of barium carbonate, I produce an excellent cementing material. In order to"mai ntain'a thorough admixture of the materials, which are l able to more or less separate on account of the difierent densities of the constituents, I find it preferable, but not necessary, to mix with such materials about'5% of oil, such as crude petroleum.

It is necessary that the cementing material should not pit or mar the surface of the metal parts treated and Ihave found Specification of Letters Patent.

Application filed May 15, 1909. Serial No. 496,272.

- containing Patented Feb. 15, 1910.

thus described my invention, what a fixe base.

5. Cementin or case-hardening material containing coa of the lignite or peat series and lime.

6. Gementing material containing coal of the lignite or peat series, lime and soda-ash.

7. (Jementin or case-hardening material containing coa and lime.

8. Cementin or case-hardening material containing coa lime and soda-ash.

9. Cementing or case hardening material containing soft coal and soda ash.

10. Cementing or case hardening material coal and soda ash.

In testlmony whereof, I have hereunto subscribed my name this 12th day of May,

HUGH RODMAN. Witnesses C. W. MCGHEE, Gno. G. WALKER. 

